A method of manufacturing a polarizing film in which a dichroic material is adsorbed or oriented in a polyvinyl alcohol-based resin (hereinafter referred to as a “PVA resin”) layer is well-known. Polarizing films are typically used for display devices such as a liquid crystal display (LCD). For example, a PVA resin-based polarizing film generally having a thickness of about 60 □m to 80 □m is adhered to both surfaces of a liquid crystal panel of the LCD.
PVA resins are hydrophilic. Therefore, the polarizing film is sensitive to changes in temperature or humidity, easily expands and contracts, and easily results in defects called curls. Accordingly, in order to suppress expansion and contraction and reduce an influence of temperature and humidity, a protection film is generally used by adhering to both surfaces of a PVA resin polarizing film. However, suppression of expansion and contraction is not easy when the polarizing film has a greater thickness, and stress is caused when the film is adhered to the liquid crystal panel and the like, which results in stains and the like on a screen. Also, recently, as demand for thin devices or devices having low energy consumption increases, demand for thinner polarizing films also increases.
A process of manufacturing a thin polarizing film is disclosed in, for example, Patent Document 1 and the like.